Mumford ruled out of Hawks clash

Sydney ruckman Shane Mumford has been ruled out of the Swans' clash with Hawthorn in Tasmania on Sunday.

The club on Monday diagnosed Mumford's recent back problems as an infection resulting from a cortisone injection and he started on a course of antibiotics.

Swans coach John Longmire was initially optimistic Mumford could return against the Hawks in Launceston, but on Wednesday confirmed he would not make the trip.

"We were hoping he might be right for this week but he hasn't had enough training under his belt," Longmire said prior to his side's training session at the SCG.

"He won't be playing, but we hope that Nick (Smith) and LRT (Lewis Roberts-Thomson) will certainly be named in the squad."

Mumford was a last-minute scratching from his side's round-two clash with Fremantle when he woke up with a sore back.

He returned in round three only to miss the Swans' next game due to more back complaints at training before their last-start win over North Melbourne.

Roberts-Thomson (broken cheekbone) and Smith (inner ear infection) have both missed the side's past two matches.

Sliding standard

Meanwhile, Longmire said he has no problem with Lindsay Thomas being cleared over the incident that broke young Swan Gary Rohan's leg - but says the AFL must examine the grey areas involved in similar contests.

North Melbourne's Thomas risked a three-game ban when he successfully fought a rough conduct charge at the tribunal on Tuesday night.

The AFL vowed before the season to crack down on players sliding into contests knees or feet first and the Thomas case was the second landmark charge in as many weeks, with Swans co-captain Adam Goodes earlier copping a one-week ban for sliding into Port Adelaide's Jacob Surjan.

The Swans unsuccessfully challenged that suspension, and Longmire admitted the debate over the contentious issue still had a long way to go.

"We've been in the unenviable position of being on both sides of the debate and discussion over the last week," Longmire said on Wednesday.

"Obviously with Goodesy being suspended and then Gary Rohan having a broken leg.

"I think there's still some grey areas when you're looking at everything. We certainly didn't have any problem with Lindsay getting off.

"We think that the (AFL's preseason laws of the game) DVD example they brought up was the start of a debate that needed to happen. But we think there's still some way to go...it just needs to be explored in a bit more detail.

"When I looked at the DVD example over the preseason, I completely agreed with where the AFL was heading.

"I think they're still working it out as well, which I don't have a problem with."

Longmire admitted there was still a little bit of confusion over the rules, suggesting Goodes' only alternative was to stand up - something that resulted in sickening consequences when Rohan did it on Sunday.

"As a coach I've got the responsibility of telling players how to go into certain contests ... the only alternative for (Goodes) was to stand up and would that have put him at risk?

"Well I couldn't answer that but ...that was the only alternative I guess to what Adam could have done and that was the argument we went to the tribunal with.

"The DVD incident was a real clear example the AFL brought up, but obviously there's a number of examples in games now that are grey areas.

"So we think there's still a little bit of confusion. We agree with what the AFL are doing in regards to sliding and looking into it."

Longmire suggested it was difficult to determine how similar the incidents involving Goodes and Thomas were.

"I don't know and there's split seconds in it. But ... as disappointed I am to have a player sitting in hospital with a broken leg, I'm not looking at Lindsay Thomas and saying there's any malice at all."